I've used receiver a few times on my ip7+ to remote into win7 work computer at a pinch when things came up unexpectedly and I had no alternative to hand. It wasn't a great experience but made me think receiver on ipad could be a good option when away from the office. I tried it out on my wife's air2 along with citrix x1 mouse and a Bluetooth keyboard and actually found it not much different an experience from using my 12' macbook to remote from.
Based on this I picked up a 10.5 pro last week and have used it for a couple of full days working remotely now; to be honest at a desk with keyboard and mouse I forget it's not a regular laptop. The surprise has been how well it works as a tablet in the lap along with apple pencil; on the phone the soft keyboard covers most of the desktop and is a pain to use, while on the 10.5 there is still plenty of screen visible and the soft keyboard is large enough that I can touch type passably with it. I actually found this more convenient than using the smart keyboard in the lap to the extent I took it back for a smart cover and now just carry my Microsoft folding keyboard along with the mouse to pull out for more serious typing sessions.
Couple of things to watch out for when you try it out:
- There was a problem with the version of the app released last week that led to a certificate error which would not allow you to connect. It affected enough users that they released a good previous version to the app store by the name of R1 - this was advised on citrix own website. Even after fixing the certificate issue in the latest version I've had difficulty connecting with the current release and found R1 much more stable so consider using that for now while they get their act together.
- some keyboard combinations don't work quite right either on the shift keyboard or external board. For example ctrl+arrow keys to move around a range in excel - I spend half my life doing this and thought it would be a deal breaker - if anyone knows how to get this to work I'd love to hear it?
As a workaround I've come to appreciate the extended keyboard option that lets you select your most used action keys or combinations to put on a bar above the main keyboard. I found a combination of home, end and f8 with arrow keys does most of the navigation I need